← Back to Sessions

Precise Point Positioning of Ships to Detect Tsunamis

Description: 

Precise Point Positioning (PPP) of ships could be a useful addition to existing tsunami detection frameworks. Leveraging Global Navigation Satellite System (GNSS) data to precisely track the movements of marine vessels can unveil anomalies in sea surface height indicative of tsunamis. Results are presented for the R/V Sikuliaq, a research vessel commissioned by the University of Alaska Fairbanks that has operated an external Trimble MPS865 Modular GNSS Heading Receiver since 2019. Raw RINEX GNSS data files with a sampling rate of 1 Hz from the ship were processed with PRIDE PPP-AR, an open-source software for PPP applications developed by the GNSS Research Center of Wuhan University. Utilizing this software, in tandem with further post-processing, we demonstrate the efficacy of harnessing ship positioning data for tsunami detection in two case studies: (1) the M8.2 earthquake that occurred offshore Chignik, Alaska on July 29, 2021, when the ship was in transit in the Pacific Ocean (kinematic), and (2) the Lowell Point landslide near Seward, Alaska on May 8 (UTC), 2022, when the ship was in port in Resurrection Bay (stationary). For both instances, orthometric height (height above mean sea level) was calculated from the ship elevation data, tides were modeled through OSU Tidal Prediction Software (OTPS) and removed from the resultant time series data, and signal processing techniques were employed for further analysis. The tsunami generated by the earthquake was not detectable, given its small size (synthetic models give 2 cm tsunami height at ship location); however, the diurnal and semidiurnal tides were well-observed using GNSS receiver data from the moving ship. Conversely, the tsunami was detectable for the landslide event the clear signal suggests dominant wave periods of less than one minute and an amplitude of approximately 5 cm. The standard deviation of the post-processed vertical position time series differed in both cases: 1.3 cm for the stationary case and 4 cm for kinematic case; noise in these readings can be attributed to wind and other atmospheric disturbances, as well as movement of the ship.

Session: Six Decades of Tsunami Science: From the Source of the 1964 Tsunami to Modern Community Preparedness [Poster Session]

Type: Poster

Date: 5/2/2024

Presentation Time: 08:00 AM (local time)

Presenting Author: Anne

Student Presenter: No

Invited Presentation: 

Authors